1000+ Steam Boilers, Engines, Nozzles & Turbines Multiple Choice Question Answer [Solved]

1. Willian's law states that the steam consumption per hour provided with a throttled governor is proportional to (where I.P. = Indicated power)
A. 1/(I.P)
B. 1/(I.P)²
C. I.P.
D. (I.P.)²
Answer : C

2. In a compound steam engine, the first stage of expansion is carried out in a high pressure cylinder whereas the last expansion is completed in low pressure cylinder. The diameter of high pressure cylinder is _________ the low pressure cylinder.
A. Equal to
B. Less than
C. More than
D. None of these
Answer : B

3. The diameter of fire tubes in Cochran boiler is of the order of
A. 2 cm
B. 6 cm
C. 8 cm
D. 12 cm
Answer : B

4. The ratio of heat actually used in producing the steam to the heat liberated in the furnace, is known as
A. Equivalent evaporation
B. Factor of evaporation
C. Boiler efficiency
D. Power of a boiler
Answer : C

5. The compounding of turbines is done in order to
A. Reduce speed of rotor
B. Improve efficiency
C. Reduce exit losses
D. All of these
Answer : D

6. The efficiency of a boiler is defined as
A. Ratio of heat actually used in producing steam to the heat liberated in the furnace
B. Ratio of the mass of steam produced to the mass of total water supplied in a given time
C. Ratio of the heat liberated in the furnace to the heat actually used in producing steam
D. None of the above
Answer : A

7. Adiabatic process is
A. Essentially an isentropic process
B. Non-heat transfer process
C. Reversible process
D. Constant temperature process
Answer : B

8. Willians line for the steam engine is a straight line relationship between the steam consumption per hour and
A. Indicated power
B. Brake power
C. Efficiency
D. Pressure of steam
Answer : A

9. Which of the following varieties of coals is mostly used in steam boilers?
A. Non-coking bituminous coal
B. Brown coal
C. Peat
D. None of the above
Answer : D

10. The three Ts for good combustion are
A. Temperature, time, and turbulence
B. Total air, true fuel, and turbulence
C. Thorough mixing, total air and temperature
D. Total air, time, and temperature
Answer : A

11. In regenerative air preheaters, the heat is transferred
A. From a metal wall from one medium to another
B. From heating an intermediate material and then heating the air from this material
C. By direct mixing
D. Heat is transferred by bleeding some gas from furnace
Answer : B

12. The pressure compounded impulse turbine as compared to velocity compounded turbine require __________ number of stages.
A. Same
B. Less
C. More
D. None of these
Answer : C

13. The length of Cornish boiler varies from
A. 2 to 4.5 m
B. 3 to 5 m
C. 5 to 7.5 m
D. 7 to 9 m
Answer : C

14. Calorific value of coal is of the order of
A. 200-400 kcal/ kg
B. 800-1200 kcal/ kg
C. 2000-4000 kcal/ kg
D. 5000-8000 kcal/ kg
Answer : C

15. The nozzle efficiency is the ratio of
A. Workdone on the blades to the energy supplied to the blades
B. Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
C. Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
D. None of the above
Answer : C

16. The expansion of steam in a nozzle follows
A. Carnot cycle
B. Rankine cycle
C. Joule cycle
D. Stirling cycle
Answer : B

17. A vessel into which the steam is exhausted and condensed after doing work in an engine cylinder or turbine is known as
A. Steam condenser
B. Steam boiler
C. Steam preheater
D. Economiser
Answer : A

18. The economiser is used in boilers to
A. Increase thermal efficiency of boiler
B. Economise on fuel
C. Extract heat from the exhaust flue gases
D. Increase flue gas temperature
Answer : A

19. The efficiency of steam turbines may be improved by
A. Reheating of steam
B. Regenerative feed heating
C. Binary vapour plant
D. Any one of these
Answer : D

20. The function of a piston rod is
A. To guide motion of the piston rod and to prevent it from bending
B. To transfer motion from the piston to the cross head
C. To convert heat energy of the steam into mechanical work
D. To exhaust steam from the cylinder at proper moment
Answer : B

21. Fusible plug for boilers is made of fusible metal containing tin, lead, and
A. Bismuth
B. Copper
C. Aluminium
D. Nickel
Anser : A

22. In a reaction turbine, when steam flows through the fixed blades,
A. Pressure increases while velocity decreases
B. Pressure decreases while velocity increases
C. Pressure and velocity both decreases
D. Pressure and velocity both increases
Answer : B

23. Blading efficiency is also known as
A. Stage efficiency
B. Diagram efficiency
C. Nozzle efficiency
D. None of these
Answer : B

24. In a nozzle, the effect of super-saturation is to
A. Decrease dryness fraction of steam
B. Decrease specific volume of steam
C. Increase the entropy
D. Increase the heat drop
Answer : C

25. The difference between Cornish boiler and Lancashire boiler is that
A. Former is fire tube type and latter is water tube type boiler
B. Former is water tube type and latter is fire tube type
C. Former contains one fire tube and latter contains two fire tubes
D. None/of the above
Answer : C

26. In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is
A. 0.007 bar
B. 0.053 bar
C. 0.06 bar
D. 0.067 bar
Answer : D

27. The balanced draft furnace is one using
A. Induced draft fan and chimney
B. Induced draft fan and forced draft fan
C. Forced draft fan and chimney
D. Any one of the above
Answer : B

28. When the nozzle operates with the maximum mass flow, the nozzle is said to be
A. Choked
B. Under-damping
C. Over-damping
D. None of these
Answer : A

29. A device in which some portion of waste heat of flue gases is recovered to heat the air before it passes to the furnace for combustion purpose, is known as
A. Superheater
B. Air-preheater
C. Economiser
D. Injector
Answer : B

30. A binary vapour plant consists of
A. Steam turbine
B. Steam condenser
C. Mercury boiler
D. All of these
Answer : D

31. In a reaction turbine
A. The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
B. The expansion of steam takes place partly in the fixed blades and partly in the moving blades
C. The steam is expanded from a high pressure to a condenser pressure in one or more nozzles
D. The pressure and temperature of steam remains constant
Answer : B

32. The ratio of the workdone on the blades to the energy supplied to the blades, is called
A. Blading efficiency
B. Nozzle efficiency
C. Gross or stage efficiency
D. Mechanical efficiency
Answer : A

33. The Parsons' reaction turbine has
A. Only moving blades
B. Only fixed blades
C. Identical fixed and moving blades
D. Fixed and moving blades of different shape
Answer : C

34. The artificial draught is produced by
A. Steam jet
B. Centrifugal fan
C. Chimney
D. Both (A) and (B)
Answer : D

35. Which type of boiler can meet rapid changes of load?
A. Vertical fire tube type
B. Horizontal fire tube type
C. Horizontal water tube type
D. Forced circulation type
Answer : D

36. Which of the following are boiler accessories?
A. Economiser
B. Superheater
C. Both (A) and (B)
D. None of these
Answer : C

37. The selection of type and size of a steam boiler depends upon
A. The power required and working pressure
B. The geographical position of the power house
C. The fuel and water available
D. All of the above
Answer : D

38. The turbine blades are
A. Straight
B. Circular
C. Curved
D. None of these
Answer : C

39. On Mollier chart, flow through turbine is represented by
A. Horizontal straight line
B. Vertical straight line
C. Straight inclined line
D. Curved line
Answer : B

40. Water at pressure of 4 kg/cm² and 160°C temperature when exposed to atmosphere will
A. Boil
B. Flash i.e. get converted into steam
C. Remain as it was
D. Cool down
Answer : B

41. A device used to heat feed water by utilising the heat in me exhaust flue gases before leaving through the chimney, is known as
A. Economiser
B. Fusible plug
C. Superheater
D. Stop valve
Answer : A

42. The diameter of Cornish boiler is of the order of
A. 12 m
B. 1.52.5 m
C. 23 m
D. 2.53.5 m
Answer : A

43. In case of non-condensing steam engines, the pressure of steam in the cylinder during exhaust stroke is _________ the condenser pressure.
A. Equal to
B. Lower than
C. Higher than
D. None of these
Answer : C

44. Caking coals are those which
A. Form lumps or masses of coke
B. Burn freely
C. Show little or no fusing action
D. Burn completely
Answer : A

45. In cross compounding, the cylinders are arranged
A. Side by side and each cylinder has common piston, connecting rod and crank
B. Side by side and each cylinder has separate piston, connecting rod and crank
C. At 90° and each cylinder has common piston, connecting rod and crank
D. At 90° and each cylinder has separate piston, connecting rod and crank
Answer : B

46. Locomotive type' boiler is
A. Horizontal multi-tubular water tube boiler
B. Water wall enclosed furnace type
C. Vertical tubular fire tube type
D. Horizontal multi-tubular fire tube type
Answer : D

47. In an ideal impulse turbine, the
A. Absolute velocity at the inlet of moving blade is equal to that at the outlet
B. Relative velocity at the inlet of the moving blade is equal to that at the outlet
C. Axial velocity at inlet is equal to that at the outlet
D. Whirl velocity at inlet is equal to that at the outlet
Answer : B

48. The mechanical draught _________ with the amount of smoke.
A. Increases
B. Decreases
C. Does not effect
D. None of these
Answer : B

49. At very low temperature, the melting and boiling temperatures become equal. This temperature is
A. 373°K
B. 273.16°K
C. 303°K
D. 0°K
Answer : B

50. An air preheater
A. Increases evaporative capacity of the boiler
B. Increases the efficiency of the boiler
C. Enables low grade fuel to be burnt
D. All of the above
Answer : D